added backends, improved templating, rbac

server/app/mailer/sending/smtp.py

@@ -18,6 +18,14 @@ class SmtpSendError(RuntimeError):
     """Raised when an SMTP send attempt fails."""
 
 
+@dataclass(frozen=True, slots=True)
+class SmtpLoginTestResult:
+    host: str
+    port: int
+    security: str
+    authenticated: bool
+
+
 @dataclass(frozen=True, slots=True)
 class SmtpSendResult:
     host: str
@@ -80,6 +88,34 @@ def _decode_refused(refused: dict[str, tuple[int, bytes]]) -> dict[str, tuple[in
     return normalized
 
 
+def test_smtp_login(*, smtp_config: SmtpConfig) -> SmtpLoginTestResult:
+    """Open an SMTP connection and authenticate if credentials are configured.
+
+    This is intentionally side-effect free: it does not send a message and it
+    never receives envelope or recipient data. It is used by the WebUI to check
+    whether the configured transport can be reached before a campaign is built
+    or queued.
+    """
+
+    host, port = _require_smtp_config(smtp_config)
+    smtp = _open_smtp(smtp_config)
+    try:
+        return SmtpLoginTestResult(
+            host=host,
+            port=port,
+            security=smtp_config.security.value,
+            authenticated=bool(smtp_config.username and smtp_config.password),
+        )
+    finally:
+        try:
+            smtp.quit()
+        except Exception:
+            try:
+                smtp.close()
+            except Exception:
+                pass
+
+
 def prepare_test_message(
     message: EmailMessage,
     *,